MON-384 "Beyond the Silence”: A Pendred Syndrome Case

Abstract Disclosure: A.M. Aviles Melendez: None. O. Onwudiwe: None. K. Win: None. Pendred syndrome is a rare autosomal recessive disorder, seen in 7.5-10 per 100,000 people, with biallelic inactivating mutations on SLC26A4/PDS gene on chromosome 7q22.3, which codes for pendrin protein, an anion exchanger of bicarbonate, chloride, and iodide in the inner ear, kidneys, and thyroid gland. Defective protein leads to bilateral sensorineural hearing loss from early childhood, and may cause imbalance and metabolic alkalosis. In the thyroid, pendrin plays a role in organification of iodine, and mutated protein leads to euthyroid goiter in 30-75% cases, although in less than half of cases, hypothyroidism may develop during young adulthood. We present a case of a female with Pendred syndrome with deafness-mutism, significant goiter, and hypothyroidism.Case of a 66 year-old female with past medical history of anxiety, allergic rhinitis, and Pendred syndrome, diagnosed in the setting of very large goiter since age 10, and progressive hearing loss, presenting to establish care for hypothyroidism and goiter. Experiencing shortness of breath awakening her during sleep, fatigue, and a 10 pound weight gain. Family history pertinent for sister with deafness and hypothyroidism. Patient completely deaf and mute, communicating through sign language. Neck with diffuse thyromegaly. Laboratory values showed: TSH of 2.24uIU/mL (N: 0.55-4.78uIU/mL), on levothyroxine 50mcg orally once daily, and negative thyroid peroxidase antibody. Due to potential for associated hyperparathyroidism, parathyroid hormone and calcium levels evaluated and found within normal limits.Neck X-ray showed bilateral soft tissue masses with leftward tracheal deviation.Thyroid ultrasound showed thyromegaly, with right lobe measuring 11.7 x 4.8 x 7.9cm, left lobe 9.4 x 3.6 x 7.3cm, and isthmus 1.8cm, increased from previous ultrasounds, and multiple thyroid nodules, with two dominant bilateral nodules that had benign findings on previous fine needle aspirations biopsies. Neck CT scan with similar findings, with mild to moderate tracheal narrowing. Levothyroxine did not decreased size of goiter over the years, and based on imaging and clinical findings, referral for thyroidectomy provided, pending completion, due to poor social support.This rare syndrome can have varied presentation, with hearing loss and goiter as the most prominent features. If present, suspicion should be high, with referral for genetic testing, and audiologic evaluation for potential hearing aids or cochlear implants. Thyroid function should be evaluated for potential hypothyroidism, and goiter managed with surgery if compressive symptoms present, such as in our patient. Less than 50,000 people in the US have a diagnosis, which make this case very interesting, especially since she also has hypothyroidism, and raises awareness of this uncommon syndrome in similar patients with family history of deafness. Presentation: Monday, July 14, 2025